1. Field of the Invention
The present invention relates to a shrinkproofing agent for leather, fur and woven, knit and unwoven products of natural fibers which makes these material resistant to the change in flexibility upon washing in water. More particularly, the present invention relates to a treating agent composition for leather, fur and fibrous material (hereinafter, the composition is simply referred to as "the treating agent") which, when used for treatment of leather, fur and woven, knit and unwoven fabrics of natural fibers such as animal hair, wool, silk, flax, cotton and the like or their mixed yarn fabrics with synthetic fibers at the time of washing these materials in water, can maintain the flexibility of these materials, give them excellent dimensional stability and shrink resistance and enhance their water absorption, as well as to a method for the treatment using the treating agent.
If leather, fur, and woven, knit or unwoven fabric of fibrous material is treated with the treating agent, these materials can be improved in tear strength, tensile strength and flexibility. In addition, in case of leather, a treatment with the treating agent makes easy the sewing work using a domestic sewing machine.
2. Prior Art Description
It has hitherto been considered that leather, fur and woven, knit and unwoven fabrics made of animal hair, wool, silk or natural cellulose fibers are difficult to wash in water because of hardening and shrinkage. Some of the synthetic fibers have also been in a similar situation. In the case of leather and fur, there has been an attempt to enable washing of these materials in water by sufficiently carrying out reliming or enzymic treatment in the stage of raw skin, thereafter tanning it and fatting it with Turkey red oil or the like. This method, however, has been unable to solve the problem that the material hardens and shrinks when washed in water only once or several times. In unavoidable cases, these materials have been cleaned by the method of dry cleaning or powder method. These methods, however, have been unable to remove water-soluble stains.
The surface of animal hair or wood is covered by a scale (cuticle). If the scale is entangled, it forms a felt which does not return to the original state. The felt formation is particularly marked in the process of drying the material after dipping it in water or washing it in water. In case of silk, flax, cotton and the like, too, dipping in water causes swelling and extension, and drying causes a shrinkage. In case of wool, methods for preventing the shrinkage by removing the scale (cuticle) of the surface have been devised. Thus, enzymic treatment, chlorine treatment and the like are carried out as means therefor, and the anisotropy in the coefficient of friction is reduced and the entanglement between fibers is prevented by Dylan FTC method, DCCA method or protein method. However, these methods are disadvantageous in that they make the fibrous material slippy and readily fraying. Apart from the above, the resin method can be referred to, which comprises bonding together fibers with a resin and coating the scale (cuticle) with it. The chlorinated resin method of IWS, the Kroy/resin method, the Sirolan BAP method and the DC-109 method belong to this type of methods. However, these methods are disadvantageous in that the fiber hardens and the hand is deteriorated. In cellulose fibers such as cotton, it has been conventional to stabilize the form by mercerization, hot water treatment, etc.